I cover water, climate and environmental issues for The Arizona Republic, but I am, I'm told, a water geek, which is to say I know there are 325,851 gallons in an acre-foot of water and 336 miles on the Central Arizona Project canal. I have worked in Las Vegas, where I once cuddled a baby white tiger belonging to Siegfried and Roy, in Washington D.C., where I rode in an elevator with Ted Kennedy my first day on the job, and, for the past ten-plus years, here in Phoenix. I spend too much time talking water policy in stuffy offices and meeting rooms and not enough time wading in rivers and sitting under cottonwood trees.

Steady growth in Arizona’s urban areas could push summertime temperatures higher by as much as 4 degrees Celsius, or 7 degrees as measured on Fahrenheit, scientists at Arizona State Universityconcluded.

Researchers examined projected growth rates along the so-called Sun Corridor, which stretches from Prescott south to Nogales, and included the projections in models used to calculate the effects of rising temperatures related to climate change. If the urban corridor reaches a population of 9 million by 2050 as some projections suggest, the buildings, roads, parking lots and other components of bigger cities could lead to summertime temperatures of 2 to 4 degrees Celsius higher than they are today, according to the study, released Sunday.

That could transform a 110-degree day, in Fahrenheit, to a 117-degree day.

How much urban growth affects temperatures depends on how cities spread, how much of the natural landscape is paved over and whether cities continue to emit high levels of greenhouse gases, said Alex Mahalov, the study’s co-author.

Greenhouse gases, primarily carbon dioxide produced by the burning of fossil fuels, can trap heat in the atmosphere and are considered a leading contributor to climate change.

This is how hot it is in Phoenix: The temperature hasn't dropped below 90 degrees at the official reporting station, day or night, since Aug. 6, a full week ago.

That's a lousy streak for early August, when mornings can typically start to provide a little bit of relief, especially if there's rain nearby. But once more this morning, the nighttime "cool-down" reversed course when it reached 90 degrees.

Our last sub-90 reading was just before 7 a.m. Aug. 6, after an overnight low of 88. That's seven toasty days with barely a break in the heat, not unheard-of, according to Ken Waters at the National Weather Service, but notable all the same.

The normal overnight low at Sky Harbor International Airport this time of year is 83 degrees, but the average low for the past week is a little over 91, according to weather service records. It surely helps that daytimes have been equally hot, with an average high over the past seven days of 113 degrees, also eight degrees above normal for this time of year.

During those seven days, the heat has broken five records, four for daytime highs and one for a record high minimum temperature (93 degrees on Aug. 9). UPDATE: Make that six records. The high (as of 2 p.m.) Monday was 115 degrees, two degrees above the old record.

A stubborn high pressure system has kept conditions hot and helped prevent afternoon thunderstorms from developing into something with actual rain. The airport has recorded only a trace of rain so far in August, although monsoon moisture has produced storms elsewhere in the region.

The forecast is calling for temperatures to moderate this week as storms push back into metro Phoenix and lows are predicted to settle into the 80s by midweek.

Rising temps shrink snowpack in Utah

Rising temperatures are turning snow into rain in the Utah mountains, a new study has concluded, a change that could leave reservoirs with less water for use during the warm and dry months each year.

Researchers at Utah State University's Utah Climate Center found that, over the past 50 years, the proportion of precipitation falling as snow during the winter months decreased by 9 percent. The change was a result of more rain and slightly less snow, according to the study, reported Friday by The Salt Lake Tribune.

Snowpack helps store water at higher elevations during colder months and then releases the runoff gradually, allowing water to accumulate in rivers and reservoirs. Rain can evaporate more quickly, leaving less water for the reservoirs and allowing the ground to dry up faster.

Rob Gillies, one of the study’s authors, told the Tribune that the data used by his research team points to rising temperatures as a cause of the change. He said this past winter showed what can happen: less snow fell, it melted earlier with the earlier onset of spring and conditions turned dry much more quickly.

The study, publishedin the Journal of Climate by the American Meteorological Society, focused on Utah data, but it affirms what other researchers have found in recent years, that spring is arriving earlier at higher elevations across the West and snow is melting and evaporating more quickly.

Survey finds divide in green attitudes

U.S. consumers rank last among 17 countries in steps taken to protect the environment and they don’t feel guilty about the damage they do, according to a survey released last week by the National Geographic Society.

The survey, called the Greendex, examines sustainable behavior, such as the type of energy used to heat or cool homes, the type of vehicle driven or the source of food, along with knowledge of environmental issues.

Consumers in China, India and Brazil scored the highest in the survey for their actions and choices, the society reported. Japan, Canada and the United States were the three lowest-scoring nations.

The survey asks consumers if they feel guilty about the impact they have on the environment. Although 47 percent of Americans said their individual choices could make a difference in protecting the environment, just 21 percent said they felt guilty about the impact their choices had.

Consumers in India, China and Brazil, meanwhile posted high Greendex scores and also said they felt guilty about how their actions affected the environment, the survey found.

The survey uses data and responses from 17,000 people in 17 countries to generate the Greendex score.

Power providers in four Western states want the federal government to help stop the flow of quagga mussels from Lake Mead into other rivers and reservoirs, the Associated Press reported Tuesday.

The Northwest Power and Conservation Council, which represents interests in Idaho, Montana, Oregon and Washington, has asked for $2 million in federal aid to help inspect and decontaminate boats that may be carrying the thumbnail-sized mollusks, the AP said.

The power providers say officials at Lake Mead and other quagga-infested reservoirs aren't doing enough to keep boats and other watercraft from transporting mussels to other locations, where they could begin multiplying and potentially damage dams or power turbines.

"A second line of defense is not as good perhaps as stopping them at Lake Mead, but it's something we absolutely need to do when we can't depend on interdiction efforts," said Phil Rockefeller, Washington's appointee on the council.

Quagga mussels were first discovered in Lake Mead in 2007. Biologists suspect the tiny mollusks hitched a ride on a boat that had been in the Great Lakes region, which has been troubled by quagga and zebra mussels for years.

The mussels have since spread to other reservoirs on the lower Colorado River, to Lake Pleasant north of Phoenix and to lakes and reservoirs in neighboring states.

Idaho state Rep. Eric Anderson, a Republican, says more effort must be focused on the Southwest's Ground Zero for the quaggas.

"The fire is Lake Mead," Anderson said in the AP story. "We can't allow any more boats to come out of Lake Mead that aren't decontaminated."

To prove his point, Anderson left 500 Idaho license plates near a marina at Lake Mead. He plans to retrieve them once they've become encrusted with mussels and then distribute them back home.

Lake Mead officials insist they're doing as much as they can to contain the problem, but balk at suggestions that they question boaters about their next destination and then report for information to other states.

Dark clouds piled up over Flagstaff Saturday and as the afternoon wore on, bands of virga smudged the horizon, confirming the increase in moisture. Rain was imminent, surely.

And then it wasn't. By sunset, the clouds had broken up and, aside from a moment earlier when those of us wandering the streets downtown peered in the sky, asking each other if that was a raindrop, maybe it was, maybe finally, the monsoon fizzled once again.

On a more typical July day up north, thundershowers dampen the afternoons routinely, but this year, the pattern has yet to establish itself. Since the June 15 start of the monsoon, the National Weather Service in Flagstaff has recorded just 0.01 of an inch of rain, compared to more than half an inch at this time last year.

On Sunday, rain actually fell, but only a trace was recorded. So where is the monsoon? The weather service in Flagstaff producedthis graphic and discussion, which notes that much of the moisture from the southwest has been driven into far eastern Arizona and New Mexico, leaving the northern high country dry and nearly four-tenths of an inch behind the average for July.

Phoenix has received 0.14 of an inch so far, all of it one storm. That's nearly normal for July and the forecast for the week includes chances of thunderstorms by Wednesday and Thursday. Tucson, meanwhile, is having a wet monsoon so far, measuring 1.2 inches of rain since the official start of the season June 15.

The monsoon is notoriously difficult to forecast, but climate experts saw reason to believe this year's season could deliver normal or above-normal precipitation. And, meteorologically, the season has really just begun in the past week, so there's lots of time for the rain gauges to fill. (Weather trivia: By the old measure of three consecutive days with dew point temperatures of 55 degrees or higher, the monsoon began July 3.)

Smoke from a fire on the Tonto National Forest pushed dust pollution levels across Phoenix into the unhealthy zone early Wednesday, adding to already high levels of ozone. The result by midday: three pollution health watches.

The Arizona Department of Environmental Quality and the Maricopa County Air Quality Department extended an ozone health watch from Tuesday and then posted same-day health watches for PM-2.5, pollution from dust particles 2.5 microns or less in diameter, and PM-10, particles 10 microns or less in diameter.

It's not common to see alerts for all three pollutants at the same time because they typically form under differing conditions.

The dust built up after winds blew smoke down into the Valley from the Poco FIre, burning near Payson. The smoke settled in over night, producing layers of haze that obscured the mountains during the morning hours. The smoke triggered alerts at air quality monitors for fine dust pollution, resulting in the PM-2.5 health watch.

PM-10 levels continued to rise as well, leading to a second same-day health watch as concentrations accumulated.

The dust alerts include restrictions on open burning and recommendations to avoid physical exertion outdoors.

Ozone, formed when heat and sunlight react with vehicle exhaust and other nitrogen oxides, is an invisible pollutant so it was not contributing to the haze, but levels had been high for several days as hot weather persisted. The ozone health watch has been extended through Thursday.

All three pollutants are bad for people to breathe. Ozone can cause shortness of breath and worsen existing respiratory ailments and, over time, can scar lung tissue. Dust invades lungs and impedes breathing. It is especially dangerous for people with asthma and similar problems. PM-2.5 can move from the lungs into the bloodstream and the heart.

Children and older people are especially vulnerable to the pollutants, but on bad air days, anyone can feel the ill effects and can suffer damage to the heart and lungs. Air quality officials recommend limiting activities outdoors when levels are high. To help control pollution, individuals can drive less, steer clear of unpaved roads and avoid using leaf blowers.

As if all that wasn't enough, the National Weather Service had issued an excessive heat watch for Wednesday, adding to the risks of leaving the house or the office.

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